Re: [rules-users] Rules with from always loops (Drools 4.0.7)

Michal is correct. Every time a "from" expression is executed, Drools does not know if a result for the expression is new or not and it creates a new fact handle, bypassing the no-loop. []s Edson 2009/2/13 Michal Bali <michalbali(a)gmail.com <mailto:michalbali@gmail.com>> This is what I think is going on: when you call update($fact1) it will first retract $fact1 which in turn retracts $fact2, the $fact1 is then inserted again which cause another 'from' evaluation and a NEW $fact2 is pulled -> no-loop doesn't work because Drools sees it as different data I am just guessing here ... On Fri, Feb 13, 2009 at 9:12 AM, Przemysław Różycki <P.Rozycki(a)amg.net.pl <mailto:P.Rozycki@amg.net.pl>> wrote: Hello, Doesn't really anyone have any logical explanation of why such a rule loops? To remind the rule: rule "Hello World" no-loop when $fact1 : MyFactBean1( ) $fact2 : MyFactBean2( ) from $fact1 then System.out.println("Fired!!!"); update($fact1); end If I don't use 'from' everything is fine. I really didn't find in a documentation, that 'from' causes any special behaviour of the rule looping. Best regards, -- Przemysław Różycki AMG.net, A Bull Group Company ul. Łąkowa 29 90-554 Łódź www.amg.net.pl <http://www.amg.net.pl> Przemysław Różycki pisze: Thanks for answer, Vikrant, but I don't think so. I have always used no-loop without any additions and it worked (when I didn't use from). BTW, if you comment a condition with from, then the rule does not loop. I also checked with "no-loop true" and result is the same. Best regards, Przemek Vikrant Yagnick pisze: I have to quickly recheck the documentation by I think you have to write "no-loop true". Just writing no-loop defaults to false I guess. -----Original Message----- From: rules-users-bounces(a)lists.jboss.org <mailto:rules-users-bounces@lists.jboss.org> [mailto:rules-users-bounces@lists.jboss.org <mailto:rules-users-bounces@lists.jboss.org>] On Behalf Of Przemyslaw Rózycki Sent: Tuesday, February 10, 2009 3:24 PM To: Rules Users List Subject: [rules-users] Rules with from always loops (Drools 4.0.7) Hello, why does such a rule always loop? Even if no-loop is used? rule "Hello World" no-loop when $fact1 : MyFactBean1( ) $fact2 : MyFactBean2( ) from $fact1 then System.out.println("Fired!!!"); update($fact1); end The full code of my test application and drl is attached. Best regards, -- Przemysław Różycki AMG.net, A Bull Group Company ul. Łąkowa 29 90-554 Łódź www.amg.net.pl <http://www.amg.net.pl> MASTEK LTD. Mastek is in NASSCOM's 'India Top 20' Software Service Exporters List. In the US, we're called MAJESCOMASTEK ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Opinions expressed in this e-mail are those of the individual and not that of Mastek Limited, unless specifically indicated to that effect. Mastek Limited does not accept any responsibility or liability for it. This e-mail and attachments (if any) transmitted with it are confidential and/or privileged and solely for the use of the intended person or entity to which it is addressed. Any review, re-transmission, dissemination or other use of or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. This e-mail and its attachments have been scanned for the presence of computer viruses. It is the responsibility of the recipient to run the virus check on e-mails and attachments before opening them. If you have received this e-mail in error, kindly delete this e-mail from desktop and server. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org> https://lists.jboss.org/mailman/listinfo/rules-users -- Edson Tirelli JBoss Drools Core Development JBoss, a division of Red Hat @ www.jboss.com <http://www.jboss.com> ------------------------------------------------------------------------ _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users